From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [RFC] virtio-mmio: Update the device to OASIS spec version Date: Tue, 20 Jan 2015 19:56:30 +0200 Message-ID: <20150120175630.GB2706@redhat.com> References: <20150115175132.GA30453@redhat.com> <1421345477.4601.9.camel@arm.com> <20150115182903.GA30947@redhat.com> <1421347322.4601.13.camel@arm.com> <20150115191203.GA31136@redhat.com> <1421689554.17436.30.camel@arm.com> <20150119183647.GB5336@redhat.com> <1421774303.14076.19.camel@arm.com> <20150120174425.GA2706@redhat.com> <1421776271.14076.21.camel@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <1421776271.14076.21.camel@arm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: Pawel Moll Cc: "virtualization@lists.linux-foundation.org" List-Id: virtualization@lists.linuxfoundation.org On Tue, Jan 20, 2015 at 05:51:11PM +0000, Pawel Moll wrote: > On Tue, 2015-01-20 at 17:44 +0000, Michael S. Tsirkin wrote: > > Good. But your current code will also try to support a mix: device that > > uses the new transport underneath, but old layout and semantics on top. > > It will not try to support the mix, but rather will not stop it from > working. > > > This has no value: the spec does *not* define such devices > > and it also does not match any hosts, so this just adds to support matrix. > > And if linux supports it, someone *will* ship such a > > device and we'll be stuck with it forever. > > > > So please, detect out of spec devices and fail gracefully. > > pci and s390 do this already. > > Ok, let it be. Will send v2 in a second. > > Pawel Thanks! The relevant functions are finalize_features (to check feature bit) and probe (to check is_legacy). -- MST